Reaction engineering studies in a polytropic fixed‐bed reactor over a highly active and selective catalyst for oxidative methane coupling

The oxidative coupling of methane (OCM) was carried out in a polytropic fixed‐bed reactor applying a Zr/La/Sr catalyst developed by the Neste company. Over this catalyst the OCM reaction follows a complex reaction scheme which includes primary parallel reaction steps to CO, CO 2 and C 2 H 6 and consecutive reactions of ethane to ethylene or CO x . Yield of higher hydrocarbons C 2+ obtained with this catalyst strongly depended on reaction conditions, i.e. low partial pressures of methane and oxygen obtained by diluting the feed gas with nitrogen and high reaction temperatures promoted C 2+ selectivity and yield. The maximum yield amounted to 21.4% (20 Vol.‐% CH 4 , 9 Vol.‐% O 2 , 71 Vol.‐% N 2 , T = 860°C; X CH4 = 41.8%, S   C   2+= 52.5%). This result belongs to the highest yields reported in the open literature.